In a small pot, heat 1 cup water with 1 cup sugar. Bring to a boil until sugar has dissolved. Remove from heat and let cool.
In a blender, combine cooled simple syrup, lime juice, sliced peaches, and chopped ginger. Blend until smooth. Pour through a fine strainer (or cheesecloth).
Pour limeade into pitcher. Add remaining 1 1/2 cup water. Stir to combine. Taste and add more water if necessary. Keep chilled in the fridge until ready to serve.